The present invention is directed to a pressure transducer which is utilized to record changes in pressure of gas or gaseous mixture as it advances across a defined passageway. Such pressure transducers convert mechanical inputs, such as pressure differentials, to electrical signals by means of a piezoelectric ceramic element.
Pressure transducers have had widespread use in such areas as aerodynamic installations, shock tubes, detonation tubes, pneumatic systems, and the like, where pressure gradients must be measured and recorded, as well as the velocity of the rapidly moving plasma, or gas. During such testing and operational uses, pressure changes are extreme, and a highly sophisticated and sensitive element must be provided that will measure such changes so that analysis may be made on the system.
However, it has been the case thus far, that due to the rapid changes in pressures caused by the shock wave in such uses as described, that extraneous, or parasitic, osillations act upon the sensing piezoelectric crystal so that the final measurement is distorted. Such parasitic oscillations, or vibrations, are either of the acoustic type, as during the rapid passage of the plasma past the sensing element, or parasitic oscillations that affect the actual structure of the transducer that mounts the piezoelectric crystal so that the extraneous vibrations impinging upon the housing will be transmitted to the piezoelectric crystal sensing element mounted within the housing. It is, therefore, of extreme importance to mount the piezoelectric crystal sensing element within the housing in such a way as to damp all such parasitic vibrations so only the pressure differential of the plasma or gas is measured.